Exxon Mobil(XOM) said in a statement Tuesday that is "fully complying with the [Securities and Exchange Commission's] request for information," saying the regulatory agency is "the appropriate entity" to review how the company has valued its assets.

Schneiderman's office is looking into why Exxon has not downgraded the estimated value of its oil reserves -- even as oil prices have faced a two-year decline. His office is also investigating whether the company has properly accounted for the impact of heightened greenhouse gas regulations on its business.